Aim: To design and develop a new nanocarrier appropriately engineered for the adequate accommodation of a virus-like particle, the recombinant hepatitis B surface antigen (22 nm), and intended to be used for the transmucosal delivery of the associated antigen. The nanoparticles consisted of a core blend of poly(D,L-lactide-co-glycolide) and poloxamer 188, and a hydrophilic shell of chitosan.
Results: By by conveniently adapting the nanoprecipitation technique, it was possible to associate a significant amount of active antigen (44%) to the nanocarrier. The resulting nanosystems had a size of around 200 nm and positive zeta potential attributed to the association of chitosan. The nanoparticles were able to deliver the associated antigen in a controlled manner for up to 14 days without compromising its activity, as determined by ELISA. Moreover, the antigenicity of the recombinant hepatitis B surface antigen was preserved for at least 14 days, when stored as an aqueous suspension, and for at least 3 months when converted in a freeze-dried powder.
Conclusion: Poly(D,L,lactic-co-glycolic acid)-based nanoparticles represent a promising approach for the delivery of virus-like-particles.